FDA Orders Class-Wide Vision-Loss Warning on GLP-1 Drugs From Eli Lilly and Novo Nordisk

The U.S. Food and Drug Administration on November 9 required all glucagon-like peptide-1 (GLP-1) receptor agonists to update their prescribing labels with a warning about a potential increased risk of non-arteritic anterior ischemic optic neuropathy (NAION), a rare eye condition that can cause permanent vision loss. The change goes into the Warnings and Precautions section rather than a boxed warning. It is class-wide: the FDA's drug safety communication names Novo Nordisk's (NVO) Ozempic, Wegovy and Rybelsus, Eli Lilly's (LLY) Mounjaro, Zepbound and its newly approved oral drug Foundayo, and older diabetes products such as Victoza and Trulicity.

The evidence is real but the absolute risk is small. An FDA meta-analysis of 126 trials covering more than 134,000 patients found 6.4 NAION events per 100,000 patient-years among GLP-1 users versus 3.8 among comparators. In observational data, GLP-1 users showed a 43% higher risk than patients on DPP-4 inhibitors, while the difference against SGLT-2 inhibitors was not statistically significant. Drug Discovery & Development summarized the case as mixed evidence behind a class-wide warning.

Both companies pushed back on causation. A Novo Nordisk spokesperson said the data do not "establish a cause-and-effect relationship," and Lilly said it is carefully evaluating the update and will respond to the FDA promptly. The label lands amid litigation: dozens of patients have sued Novo Nordisk and Eli Lilly over vision loss, and in Europe NAION has been listed as a very rare side effect of semaglutide since a 2025 review by the European Medicines Agency.

What to watch: weekly prescription data for any slowdown in new starts, how plaintiffs use the new label language in pending cases, and physician guidance on monitoring. Because the warning covers every drug in the class, it does not hand either Lilly or Novo a safety advantage over the other; the commercial question is whether it dampens overall demand for the category.